/Engine/Source/Runtime/GeometryFramework/Public/Components/DynamicMeshComponent.h
Support for Component attachment change notifications via delegates. Standard UE Actor/Component hierarchy does not generally provide these capabilities, but in some use cases (eg procedural mesh Actors) we need to know things like when the Component set inside an Actor is modified.
typedef TMulticastDelegate_TwoParams< void, [USceneComponent](API\Runtime\Engine\Components\USceneComponent) *, bool > FComponentChildrenChangedDelegate